containerd/content/content.go
Stephen J Day 8be340e37b
content: remove Provider.Reader
After some analysis, it was found that Content.Reader was generally
redudant to an io.ReaderAt. This change removes `Content.Reader` in
favor of a `Content.ReaderAt`. In general, `ReaderAt` can perform better
over interfaces with indeterminant latency because it avoids remote
state for reads. Where a reader is required, a helper is provided to
convert it into an `io.SectionReader`.

Signed-off-by: Stephen J Day <stephen.day@docker.com>
2017-08-09 14:32:28 -07:00

99 lines
2.6 KiB
Go

package content
import (
"context"
"io"
"time"
"github.com/containerd/containerd/oci"
"github.com/opencontainers/go-digest"
)
type ReaderAt interface {
io.ReaderAt
io.Closer
Size() int64
}
type Provider interface {
ReaderAt(ctx context.Context, dgst digest.Digest) (ReaderAt, error)
}
type Ingester interface {
Writer(ctx context.Context, ref string, size int64, expected digest.Digest) (Writer, error)
}
// TODO(stevvooe): Consider a very different name for this struct. Info is way
// to general. It also reads very weird in certain context, like pluralization.
type Info struct {
Digest digest.Digest
Size int64
CreatedAt time.Time
UpdatedAt time.Time
Labels map[string]string
}
type Status struct {
Ref string
Offset int64
Total int64
Expected digest.Digest
StartedAt time.Time
UpdatedAt time.Time
}
// WalkFunc defines the callback for a blob walk.
type WalkFunc func(Info) error
// Manager provides methods for inspecting, listing and removing content.
type Manager interface {
// Info will return metadata about content available in the content store.
//
// If the content is not present, ErrNotFound will be returned.
Info(ctx context.Context, dgst digest.Digest) (Info, error)
// Update updates mutable information related to content.
// If one or more fieldpaths are provided, only those
// fields will be updated.
// Mutable fields:
// labels.*
Update(ctx context.Context, info Info, fieldpaths ...string) (Info, error)
// Walk will call fn for each item in the content store which
// match the provided filters. If no filters are given all
// items will be walked.
Walk(ctx context.Context, fn WalkFunc, filters ...string) error
// Delete removes the content from the store.
Delete(ctx context.Context, dgst digest.Digest) error
}
// IngestManager provides methods for managing ingests.
type IngestManager interface {
// Status returns the status of the provided ref.
Status(ctx context.Context, ref string) (Status, error)
// ListStatuses returns the status of any active ingestions whose ref match the
// provided regular expression. If empty, all active ingestions will be
// returned.
ListStatuses(ctx context.Context, filters ...string) ([]Status, error)
// Abort completely cancels the ingest operation targeted by ref.
Abort(ctx context.Context, ref string) error
}
type Writer interface {
oci.BlobWriter
Status() (Status, error)
Truncate(size int64) error
}
// Store combines the methods of content-oriented interfaces into a set that
// are commonly provided by complete implementations.
type Store interface {
Manager
Provider
IngestManager
Ingester
}